Reciprocating electric drill



(No Model.)

P. P. LOOMIS. REGIPROCATING ELECTRIC DRILL.

No. 479,948. Patented Aug. 2, 1892.

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UNITED STATES FRANK F. LOOMIS,

PATENT OFFICE.

OF AKRON, OHIO.

RECIPROCATING ELECTRIC DRILL...

SPECIFICATION forming part of Letters Patent No.479,948, dated August 2, 1892.

Application filed April 11, 1891.

To all whmn it may concern.-

Be it known that I, FRANK F. LOOMIS, acitizen of the United States, residing at Akron, in the county of Summit and State of Ohio, have invented a certain new and useful Improvement in Reciprocating Electric Drills, of which the following is a specification.

My invention has relation to that class of electric drills wherein the reciprocating drillshaft passes through a solenoid and is actuated by the magnetic attraction generated therein.

The object of my invention is to provide new and improved devices for increasing the force of the stroke and insuring a quick return in the back-stroke by alternately increasing and reducing the attraction of the solenoid, to prevent sparking and consequent wear and destruction of the alternating circuit breaker, and generally to produce a simple and effective machine of the class designated.

To the aforesaid object my invention consists of the peculiar and novel construction, arrangement, and combination of parts hereinafter described, and then specifically pointed out in the claims, reference being had to the accompanying drawings, which form a part of this specification.

In the accompanying drawings, in which similar reference-numerals indicate like parts in the several figures, Figure 1 is a plan of a simple form of my improved drill, showing the commutator of the dynamo and the revolving circuit-breaker; Fig. 2, a section of the stroke and backstroke solenoids with the commutator and circuit-breaker, the wires on the solenoids being exaggerated in size to illustrate their construction and current connections; Fig. 3, a similar view of a modification of the machine, the commutator being omitted; and Fig. 4:, a solenoid partially wound, showing the duplex wires.

Referring to the drawings, 1 is a frame, which may be of any desired or preferred form, as taste or the requirements of the machine may determine,on which are mounted in align ment with each other and slightly separated two solenoids 2 3, through thehollow cores of which a drill-rod 4, of soft iron, freely slides, bearing on one endadetachable drill 5. Back of the frame 1 at any required distance is a commutator 6, which may be of any known Serial No. 388,537. (No model.)

or approved construction, connected with a dynamo, which it has not been deemed necessary to show, as any form may be used, as its operation is obvious, on which are the brushes 7 3 for the direct and return current, connected, respectively, with the binding posts 9 10 by wires under the base 11.

Oonfining the description to the construction shown in Fig. 2, the solenoid 3 is wound with a single insulated wire and the solenoid 2 with two insulated wires 12 13, wound side by side, as shown in Fig. 4E and represented by black and white sectional circles, respectively, in Fig. 2. The direct wire 14 from the dynamo is connected with the outer end of the wire 12, and from its inner end the current passes by the return-wire 15. A branch wire 16 from the direct wire 1% conveys the current to the inner end of the coil on the solenoid 3, from the outer end of which it passes by a branch wire 17 to the return-wire 15. Between the dynamo and branch wire 16 a branch wire 18 from the direct wire 14 leads to one binding-post of the brush of the circuit-breaker, hereinafter described, and from the opposite post a wire 19 is connected with the outer end of the wire 13 on the solenoid 2, the inner end of said wire being connected by a wire 20 with the return-wire 15. The circuit-breaker consists of a revolving cylinder 21, one half of its periphery, longitudinally divided, being non-conducting and the other half provided with multiple, as three, parallel insulated metallic plates 22. The brush, held byanonconducting clamp 23, consists of two outer plates 24, which press on the outer ends of the outer plates 22, between which are a multiple, as two, bifurcated plates 25, the two ends resting on the ends of contiguous plates 22.

By this arrangement the current reaching the first plate 24: passes successively through the plates 22 and 25 to the second plate 24. and thence to the coil 13.

In the drawings the circuit-breaker is represented as located between the drill and dynamo and run by a belt from the latter; but this location and arrangement are not material, as it may be placed at any point where a power can be obtained to run it, or it may be attached directly to the end of the commutator and run with it.

The coils of the solenoids 2 3 are so adjusted that when one wire only of the former is in the current its attraction is less than that of the latter and the center of the rod 4 is by the well-known law of solenoids drawn toward its center, producing a backstroke; but when the current passes through both wires 12 13 the attraction of the solenoid 2 exceeds that of the solenoid 3 and the rod 4 is drawn in the opposite direction, producing the front stroke.

In operation the solenoid 3 and the wire 12 of the solenoid 2 are constantly in the circuit, and the wire 13 is alternately in circuit half of each revolution of the circuit breaker, thereby communicating to the drill-rod and drill a rapid reciprocating movement. I prefer, however, to construct my improved drill as shown in Fig. 3, as I thereby increase the power of the front stroke by reducing the attraction of the solenoid Sas that of the solenoid 2 is increased. In this construction the arrangement of the parts is the same as in that shown in Fig.2 and the electrical connections of the solenoid 2 the same; but in this case I also wind the solenoid 3 with duplex wires, one of which is connected with the direct and return wires 16 17, as in the other form of construction. The other wire is connected with the direct and return wires 26 27' from a brush 28 of the circuit-breaker, which in turn is connected with the direct wire 14 by a branch 29. The coils areso adjusted that when both wires of the solenoid 3 are in circuit its attraction exceeds that of the solenoid 2 with one wire only in circuit.

In operation the second wires of the solenoids 2 3 are alternately in circuit by the revolution of the circuit-breaker, so that the attraction of one solenoid is reduced as the other is increased, thereby communicating to the rod 4 a stronger stroke in each direction.

By means of the combination of the multiple plates 22 and 24 and bifurcated plates 25 in the branch wire of the direct wire sparking at points of contact between the plates is effectually prevented.

I claim 1. In an electric reciprocating drill of the class designated, thecombination, with two duplex-wound solenoids arranged in alignment, one wire of each connected with the direct and return circuit of a dynamo and the second wires of each connected with branches from said direct and return currents, of a circuit-breaker interposed in said branch direct current and arranged to alternately connect said second wires therewith, substantially as shown and described.

2. In a reciprocating drill of the class designated, the combination, with a duplex-wound solenoid having one wire connected with the direct and return current of a dynamo and the other wire connected with a branch direct and return current and a circuit-breaker interposed in said branch direct current and arranged to intermittently break and close the circuit, of an oppositely-disposed solenoid connected with said direct and return currents and adjusted to overcome the attraction of the duplex-wound solenoid, reduced by the FRANK F. LOOMIS.

In presence of- C. P. HUMPHREY, C. E. HUMPHREY. 

